Passing through some of the most sparsely populated territory in the country, I-90 connects Seattle, Chicago, Cleveland, Buffalo, and Boston. Selected cities along the route are labeled, for reference, with cities of 250,000 or more shown in bold and with filled circles.

Median household income varies by county across the United States. Predominantly rural counties across parts of the South, Southwest, Midwest, and Appalachia have some of the lower median incomes in the country. Counties with higher median household incomes are generally located in the Boston-to-Washington corridor, in larger metropolitan statistical areas, and along the coasts.

Test your knowledge of population data! Start by choosing your geographic level: metro areas or states. Click on the name in each match-up that you think has the larger population. Green shows a correct answer, red indicates an incorrect answer. When you have opposing names picked for the next round, pick again. See how close you can come to a perfect score of 63. When you are finished, play again or mouse-over results to view the most current population estimates for each pair.

This detailed look at annual percentage change in state population over the last decade shows variation in growth patterns. In recent years, North Dakota, and the District of Columbia have had the highest growth rates, in percentage terms, in the country. States such as Nevada and Arizona, fast-growers a decade ago, have had some moderation in their growth rates but the states continue to increase in population.

The Census Flows Mapper is a web mapping application intended to provide users with a simple interface to view, save and print county-to-county migration flows maps of the United States. The data are from the 2006-2010 American Community Survey.

This graph explores variation in high school education attainment within selected race and Hispanic origin groups by sex and nativity between regions. Attainment of a high school diploma (or equivalent level of education) is generally very high in the U.S., so this graph focuses on the percentage of the population 25 and older who do not have that level of education. There are notable differences between foreign-born and native population among many groups. For example, in the West, 57 percent of Hispanic foreign-born males had less than a high school education compared with 19 percent of Hispanic native-born males. Nineteen percent of Asian foreign-born females had less than a high school diploma compared with 5 percent of Asian native-born females.

Of the major interstates in the country, I-5 passes through the second-largest population (behind only I-95 on the nation's east coast). In its path from southern California to Washington State, I-5 traverses densely populated areas of Los Angeles, Portland, and Seattle but, in contrast to the I-95 transportation corridor, there are long stretches of I-5 that pass through areas with very low population density such as California's Central Valley. Selected cities along the route are labeled, for reference.